A supporter of Polish independence, he was forced to leave the country and immigrated to New York City in 1772. He opened a dry goods store, and eventually began supplying the Continental Army during the American Revolution. Arrested by the British as a spy in 1778, he was sentenced to death. He escaped and moved to Philadelphia where he became active in finance. He sold government bonds and backed by his own fortune, raised money for the Revolution in the form of loans from France. The recession that followed the War left Salomon impoverished.